US4489432A - Method and apparatus for reproducing sound having a realistic ambient field and acoustic image - Google Patents
Method and apparatus for reproducing sound having a realistic ambient field and acoustic image Download PDFInfo
- Publication number
- US4489432A US4489432A US06/383,151 US38315182A US4489432A US 4489432 A US4489432 A US 4489432A US 38315182 A US38315182 A US 38315182A US 4489432 A US4489432 A US 4489432A
- Authority
- US
- United States
- Prior art keywords
- speaker
- location
- sub
- main
- ear
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04S—STEREOPHONIC SYSTEMS
- H04S3/00—Systems employing more than two channels, e.g. quadraphonic
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04S—STEREOPHONIC SYSTEMS
- H04S1/00—Two-channel systems
- H04S1/002—Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution
Definitions
- This invention pertains to a method and apparatus for reproducing sound from stereophonic source signals in which the reproduced sound has a realistic ambient field and acoustic image.
- the present invention can best be understood and appreciated by setting forth a generalized discussion of the manner in which stereophonic signals originate, as well as a generalized discussion of the manner in which sound is conventionally reproduced from a stereophonic signal source.
- the human auditory system localizes position through two mechanisms.
- Direction is perceived due to an interaural time delay or phase shift.
- Distance is perceived due to the time delay between an initial sound and a similar reflected sound.
- a third, poorly understood mechanism causes the ear to perceive only the first of two similar sounds when separated by a very short delay. This is called the precedence effect.
- the listener perceives the direct sound reflected from the walls of the hall. Due to the direction and distance information contained in the reflected signals the listener forms a subliminal impression of the size and shape of the hall in which the performance is taking place. Referring to FIG. 1, for example there is illustrated a source S spaced from a listener P in an environment which includes a plurality of walls, W1, W2, and W3.
- the listener will of course perceive sounds from the source S along a direct path DP1. Also, the listener will perceive sounds reflected from the walls of the environment, illustrated in FIG. 1 by the path RP1 to a point P1 on the wall W1 and thence along path RP2 to the listener P.
- microphones ML and MR are situated in front of the source S as shown in FIG. 1. If the source S is equidistant from the microphones, then both microphones will pick up sounds from the source S along direct paths DP2 and DP3.
- the hall ambience information will be recorded by the left and right microphones ML and MR in addition to the direct sound from the source. This is illustrated by the reflected paths RP3 and RP4 from the point P1 on wall W1.
- FIG. 2 there is illustrated what happens when the sounds recorded by the microphones as in FIG. 1 are reproduced by loudspeakers LS and RS positioned in the same position relative to the listener P as the recording microphones.
- the listener P is shown as having a left ear Le and a right ear Re. If the sound recorded as in FIG. 1 was initially equidistant from the two microphones, the sound will reach each microphone at the same time. Accordingly, in reproducing the sound, a listener equidistant from the two speakers LS and RS will hear the reproduced direct sound from the left speaker in the left ear (path A) at the same time as the same sound from the right speaker is heard in the right ear (path B). The precedence effect will tend to reduce perception of interaural crosstalk paths a and b. The listener P, hearing the same sound in both ears at once will localize the sound as being directly in front of and between the speakers, as shown in FIG. 3.
- the listener When reproduced by the loudspeakers LS and RS the listener will first hear the direct sound from the source at the same time in both ears, corresponding to the apparent source shown in FIG. 4. The listener will then hear the delayed sound corresponding to the reflection from P1 being recorded by the left microphone and reproduced by the left speaker first in the left ear Le and then in the right ear Re. The initial delay caused by the longer path taken by the reflection in reaching the left microphone ML gives the listener an impression of the distance between the original source, P1, and himself.
- the interaural delay ⁇ t (corresponding to the time it takes sound to travel between a listener's ears) gives the impression that the reflected sound has come from a point behind and in the same direction as the left speaker, illustrated as the first apparent point P1 in FIG. 4.
- the location of the actual point P1 is also shown in FIG. 4.
- the listener will hear the reflected sound reproduced by the right speaker RS. Since the additional delay (correspondinq to the distance MD in FIG. 1) is much greater than any possible interaural delay (except for the case of a verv small microphone spacing) this sound will create a second apparent point P1 behind and in the same direction as the riqht speaker, as illustrated in FIG. 4.
- the path lengths to the two microphones ML and MR will be such that the differences in arrival times of the reflected sound at the two microphones will be comparable to a possible value of interaural time delay.
- the reflected sound from point P2 to the left microphone ML along path d' would be approximately equal to the path length c' to the right microphone MR plus the interaural time delay ⁇ t.
- d' equals c'+ ⁇ t.
- each possible value of interaural time delay corresponds to an angle of incidence for the perceived sound within a 180° arc.
- the apparent direction of the sound would swing rapidly to the right or left. In practice this is limited by the listening angle of the loudspeakers.
- the interaural crosstalk signal of the opposite speaker gradually takes precedence effectively limiting the apparent sound sources to within the listening angle of the speaker.
- U.S. Pat. No. 4,058,675 to Kobayashi et al discloses a means for cancelling interaural crosstalk using inverted and delayed versions of the left and right stereo signals fed to a second pair of speakers arranged to produce the correct geometry.
- the Kobayashi et al device is only partially effective.
- Carver discloses in U.S. Pat. No. 4,218,585 an electronic device for cancelling interaural crosstalk. This device inverts one stereo signal, splits it into several components, delays each component separately by a different amount and recombines these with a modified version of the other stereo signal. Performing this operation on both stereo signals, Carver claims to effect a cancellation of interaural crosstalk and to create a "dimensionalized effect.”
- U.S. Pat. No. 4,199,658 to Iwahara also discloses a technique for performing the interaural crosstalk cancellation.
- Iwahara uses a second pair of speakers to reproduce the cancellation signal, which is composed of a frequency and phase compensated version of the inverted main signal.
- This cancellation signal is fed to a speaker just outside the main speaker on the opposite side from which the cancellation signal was derived.
- the necessary delay is accomplished acoustically by the placement of the sub-speakers and detailed consideration is given to the phase and frequency compensation required to accomplish the cancellation.
- a binaural signal input is specified. It will be seen later why a binaural input is essential to the correct function of an interaural crosstalk cancellation system.
- FIG. 7 shows an off axis source whose signal arrives at the right microphone ⁇ t later than at the left microphone.
- ⁇ t is equal to the maximum possible interaural time delay.
- FIG. 8 shows the apparent source displaced far to the left of the listener, which it would appear to the listener in such a circumstance.
- a right main speaker and a left main speaker are provided respectively at right and left main speaker locations which are equidistantly spaced from a listening location.
- the listening location is defined as a spatial position for accommodating a listener's head facing the main speakers and having a right ear location and a left ear location along an ear axis, with the right and left ear locations separated along the ear axis by a maximum interaural sound distance of ⁇ t max , and the listening location being defined as the point on the ear axis equidistant to the right and left ears.
- a right sub-speaker and a left sub-speaker are provided at right and left sub-speaker locations which are equidistantly spaced from the listening location.
- the right and left channel outputs are coupled respectively to the right and left main speakers.
- a left channel minus right channel signal is developed and coupled to the left sub-speaker and a right channel minus left channel signal is developed and coupled to the right sub-speaker.
- FIG. 1 is a diagram of the typical environment in which stereophonic recordings are made.
- FIG. 2 is a diagram illustrating conventional stereophonic sound reproduction, and showing interaural crosstalk paths.
- FIG. 3 is a diagram showing the apparent source as perceived by a listener for a sound source equidistant from the recording microphones when the sound is reproduced over a pair of speakers.
- FIG. 4 is a diagram illustrating the location of apparent sources to a listener when a stereophonic recording is reproduced, taking into account reflection of sound from the walls of the hall in which the recording was made.
- FIG. 5 is a diagram illustrating a situation where path lengths to two recording microphones for reflected sounds is such that the difference in arrival times of the reflected sound of the two microphones is comparable to a possible value of interaural time delay.
- FIG. 6 is a diagram showing how each possible value of interaural time delay corresponds to an angle of incidence for perceived sounds within a 180° arc.
- FIG. 7 is a diagram illustrating an off-axis source whose signal arrives at the right microphone ⁇ t later than at the left microphone, where ⁇ t is equal to the maximum possible interaural time delay.
- FIG. 8 illustrates the apparent source that would appear to a listener for the situation shown in FIG. 7 when the recording were reproduced on a pair of speakers.
- FIG. 9 is a diagram showing use of main speakers and sub-speakers in accordance with the invention.
- FIG. 10 is a diagram illustrating an apparent source location as produced by the arrangement of FIG. 9.
- FIG. 11 illustrates an embodiment of the invention in which the sub-speakers and main speakers are commonly mounted in respective enclosures.
- a left main speaker LMS and a right main speaker RMS are disposed at left and right main speaker locations along a speaker axis and the left and right main speakers are equidistantly spaced from a listening location.
- the listening location is defined as the point common to a listening axis perpendicular to the speaker axis and equidistantly spaced from the main speakers, and to the ear axis at a point midway between the left ear Le and right ear Re of a person P.
- a left sub-speaker LSS and a right sub-speaker RSS are also provided at left and right sub-speaker locations which, in accordance with this one embodiment, are situated on the speaker axis.
- the left and right sub-speakers are also equidistantly spaced with respect to the listening location.
- the right and left main speakers are fed the right and left channel stereo signals, respectively.
- the sub-speakers, positioned outside the left main speaker and outside the right main speaker are fed the difference signals left channel minus right channel and right channel minus left channel, respectively.
- stereo difference signals left channel minus right channel and/or right channel minus left channel
- U.S. Pat. No. 3,697,692 to Hafler describes a method of synthesizing 4-channel sound using rear speakers fed by a difference signal. This system was later made commercially available as the Dynaco QD-1 "Quadaptor".
- U.S. Pat. No. 4,308,423 to Cohen describes an electronic device for cancelling interaural crosstalk and amplifying off-axis stereo images. This is accomplished by creating a difference signal, left minus right, which is electronically delayed and mixed with the main left signal.
- the inverted difference signal right minus left is delayed electronically and mixed with the main right signal.
- Cohen describes this technique as a method of cancelling interaural crosstalk without "muddying" the central region and without reducing bass output. Cohen does not, however, present any detailed analysis of the effects of this system on the reproduction of recorded sound.
- the present invention as shown in FIG. 9 accomplishes many of the same ends as the Cohen U.S. Pat. No. 4,308,423 through purely acoustic means, and with some advantages over Cohen. That the present invention also produces a realistic treatment of recorded material will be seen from the following analysis.
- the left and right signals as functions of time. Specifically, distances will be expressed as sound distances, which correspond to the time it takes sound to travel the distance in question.
- the time required for sound from the main right speaker RMS to reach the right ear Re is t.
- the signal at the right ear from this speaker will be designated R(t).
- the quantity ⁇ t is the interaural time delay corresponding to the listening angle of the speakers relative to the listener as shown in FIG. 9, and ⁇ t' is the delay of the difference signal, e.g. R-L, relative to the main signal, e.g. R, as determined by the relative placement and orientation of the speakers and listener as shown in FIG. 9.
- the signals arriving at the left and right ears would be:
- FIG. 10 illustrates the apparent source that a listener would perceive in such a situation. Referring to FIG.
- the right ear would hear the same signal at the same time as the left ear, but at half the strength.
- the listener will perceive the apparent sound source as slightly shifted to the left of center between the speakers.
- the left ear will perceive only the main signal, L(t), since the other signals are weaker and later.
- the right ear however, has a half strength signal which arrives first followed by a full strength signal delayed by ⁇ t.
- the precedence effect does not fully mask the late arrival of the stronger signal so that the listener perceives, at least slightly, a direction cue placing the apparent sound source at a listening angle corresponding to an approximate interaural delay slightly less than ⁇ t. This will place the apparent sound source nearly out to the left speaker.
- the difference signal is reduced gradually to zero as the channels become equal.
- the inter-speaker delay ⁇ t' between the respective main and sub-speakers along the listening angle between the speakers and the listening location must be greater than the interaural delay ⁇ t as shown in FIG. 9 along the listening angle of the listening location with respect to the speaker locations by enough to insure the desired function of the precedence effect as outlined above.
- ⁇ t equals ⁇ t' the effect is not unpleasant, it is just that the optimum ambience information is not present in the reproduced sound field.
- ⁇ t' is greater than ⁇ t, in order to obtain the best image quality outside the listening angle of the speakers, ⁇ t' should be close enough to ⁇ t such that a substantial cancellation of interaural crosstalk occurs.
- values of ⁇ t' about 1.2 times greater than ⁇ t provide a suitable compromise and provide a realistic ambient field and acoustic image.
- the left and right main and sub-speakers are located at respective main and sub-speaker locations arranged on a speaker axis which is parallel to an ear axis of a listener in a normal listening position along a listening axis equidistant from the two sets of speakers.
- a speaker axis which is parallel to an ear axis of a listener in a normal listening position along a listening axis equidistant from the two sets of speakers.
- the main and sub-speakers may be very similar, if not identical, in construction. This will assure that differences in acoustic position of dissimilar drive units or differences in phase shift of dissimilar cross-over networks will not occur and hence not degrade the performance of the system. Additionally, it should be understood that in order to obtain the best performance from the system that there are some limitations on the placement of the speakers relative to the listener.
- the sum of ⁇ t+ ⁇ t' (FIG. 9) should never exceed the maximum possible interaural time delay ⁇ t max corresponding to a distance along the ear axis.
- ⁇ t max corresponds to the time it takes sound to travel such a distance.
- the condition that the sum of ⁇ t and ⁇ t' should not exceed the maximum possible interaural time delay ⁇ t max can be met in practice if the distance between the left and right main speakers D along the speaker axis is always less than the perpendicular distance from the listening location along the listening axis D' with respect to the speaker axis.
- the spacing D between the main speakers is on the order of 0.7 to 0.9 times as large as the distance D'.
- D gets very close to D', the realistic ambient field and enhanced acoustic image that is otherwise obtained begins to disappear.
- the left main speaker and the left sub-speaker may be commonly mounted in a single enclosure LE, and the right main speaker and right sub-speaker are commonly mounted in a common enclosure RE.
- This has the advantages of fixing the inter-speaker delay ⁇ t', and offers the advantage that only two speaker enclosures are required.
- a spacing between the main and sub-speakers of eight inches, with the main and sub-speakers being identical two-way loudspeakers each having a six inch woofer and a one inch tweeter was found to work well.
- a main to sub-speaker spacing of eight inches, and assuming an ear spacing between the left and right ears of approximately 6.5 inches this yields a value of ⁇ t' approximately 1.2 times greater than ⁇ t, as discussed herein before as a suitable compromise.
- the difference signals left channel minus right channel and right channel minus left channel which have been referred to throughout this description are easily obtained in practice by connecting the sub-speakers across the left plus and right plus terminals of a stereophonic amplifier's outputs. Connecting left plus to the plus speaker terminal of the left sub-speaker and right plus to the sub-speaker common or normal ground terminal will give a signal corresponding to the left channel minus right channel. Reversing this connection will give a signal to the right sub-speaker corresponding to the right channel minus the left channel.
- the known techniques for cancelling interaural crosstalk if successful in their stated aim, create an unnatural impression when reproducing sounds, particularly ambient sounds, far off the equidistant axis of two microphones placed farther apart than ear spacing.
- the present invention creates a realistic acoustic image regardless of the position of the recorded source.
- this realistic ambient field and acoustic image is created in accordance with the present invention with commonly available recorded material and does not require a specially recorded input signal.
- the present invention is a purely acoustic implementation requiring no special electronic components and utilizing the unmodified output from a standard stereophonic high fidelity system.
- the present invention recognizes the advantages of certain specific values of delay and sets forth a technique for fixing this value relative to the listener, i.e. incorporating the main and sub-speaker for each channel in a common enclosure, thereby offering increased simplification of set-up and operation to the user.
- the performance of the present invention is not subject to the inevitable degradation caused by extra stages of electronic signal processing.
- the invention described herein is a novel apparatus and method for creating a realistic impression of sounds reproduced from commonly available recorded material. It offers performance advantages over those techniques and apparatus described in the prior art, and is utterly straightforward and simple in its preferred embodiments.
- the invention has been described herein with respect to certain preferred embodiments, it is not intended to limit the invention to any specific details of those preferred embodiments. That is, it should be clear that various modifications and changes can be made to those preferred embodiments without departing from the true spirit and scope of the invention, which is intended to be set forth in the accompanying claims.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Stereophonic System (AREA)
Abstract
Description
L(t)+L(t+Δt')-R(t+Δt')+R(t+Δt)+R(t+Δt+Δt')-L(t+Δt+Δt') (1)
R(t)+R(t+Δt')-L(t+Δt')+L(t+Δt)+L(t+Δt+Δt')-R(t+Δt+Δt') (2)
L(t)+L(t+Δt')-L(t+Δt+Δt') (3)
-L(t+Δt')+L(t+Δt)+L(t+Δt+Δt') (4)
L(t)+L/2(t+Δt')+L/2(t+Δt)-L/2(t+Δt+Δt') (5)
L/2(t)+L(t+Δt)-L/2(t+Δt')+L/2(t+Δt+Δt') (6)
L(t)+L(t+Δt)-L/2(t+Δt+Δt') (7)
L/2(t)+L/2(t+Δt)-L/2(t+Δt+Δt') (8)
L(t)+L/2(t+Δt)+L/2(t+Δt')-L/2(t+Δt+Δt') (9)
L/2(t)+L(t+Δt)-L/2(t+Δt')+L/2(t+Δt+Δt') (10)
Claims (14)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/383,151 US4489432A (en) | 1982-05-28 | 1982-05-28 | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
GB08314479A GB2122459B (en) | 1982-05-28 | 1983-05-25 | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
JP58092567A JP2529933B2 (en) | 1982-05-28 | 1983-05-27 | Sound reproduction method with realism and sound image |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/383,151 US4489432A (en) | 1982-05-28 | 1982-05-28 | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
Publications (1)
Publication Number | Publication Date |
---|---|
US4489432A true US4489432A (en) | 1984-12-18 |
Family
ID=23511944
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/383,151 Expired - Lifetime US4489432A (en) | 1982-05-28 | 1982-05-28 | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
Country Status (3)
Country | Link |
---|---|
US (1) | US4489432A (en) |
JP (1) | JP2529933B2 (en) |
GB (1) | GB2122459B (en) |
Cited By (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4612663A (en) * | 1984-03-26 | 1986-09-16 | Holbrook Kyle A | Multichannel audio reproduction system |
US4630298A (en) * | 1985-05-30 | 1986-12-16 | Polk Matthew S | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
US4638505A (en) * | 1985-08-26 | 1987-01-20 | Polk Audio Inc. | Optimized low frequency response of loudspeaker systems having main and sub-speakers |
US4748669A (en) * | 1986-03-27 | 1988-05-31 | Hughes Aircraft Company | Stereo enhancement system |
US4841572A (en) * | 1988-03-14 | 1989-06-20 | Hughes Aircraft Company | Stereo synthesizer |
US4888804A (en) * | 1988-05-12 | 1989-12-19 | Gefvert Herbert I | Sound reproduction system |
US4910779A (en) * | 1987-10-15 | 1990-03-20 | Cooper Duane H | Head diffraction compensated stereo system with optimal equalization |
US4975954A (en) * | 1987-10-15 | 1990-12-04 | Cooper Duane H | Head diffraction compensated stereo system with optimal equalization |
US5034983A (en) * | 1987-10-15 | 1991-07-23 | Cooper Duane H | Head diffraction compensated stereo system |
US5117459A (en) * | 1990-05-03 | 1992-05-26 | Chicago Steel Rule Die & Fabricators Co. | Ambient imaging loudspeaker system |
US5136651A (en) * | 1987-10-15 | 1992-08-04 | Cooper Duane H | Head diffraction compensated stereo system |
US5274708A (en) * | 1992-06-01 | 1993-12-28 | Fusan Labs, Inc. | Digital stereo sound enhancement unit and method |
US5594801A (en) * | 1994-05-26 | 1997-01-14 | Mcshane; Charles L. | Ambient expansion loudspeaker system |
US5661808A (en) * | 1995-04-27 | 1997-08-26 | Srs Labs, Inc. | Stereo enhancement system |
US5850453A (en) * | 1995-07-28 | 1998-12-15 | Srs Labs, Inc. | Acoustic correction apparatus |
US5912976A (en) * | 1996-11-07 | 1999-06-15 | Srs Labs, Inc. | Multi-channel audio enhancement system for use in recording and playback and methods for providing same |
US5970152A (en) * | 1996-04-30 | 1999-10-19 | Srs Labs, Inc. | Audio enhancement system for use in a surround sound environment |
US6281749B1 (en) | 1997-06-17 | 2001-08-28 | Srs Labs, Inc. | Sound enhancement system |
US20020161882A1 (en) * | 2001-04-30 | 2002-10-31 | Masayuki Chatani | Altering network transmitted content data based upon user specified characteristics |
US20020181718A1 (en) * | 2001-05-29 | 2002-12-05 | Pioneer Corporation | Audio apparatus |
US6590983B1 (en) | 1998-10-13 | 2003-07-08 | Srs Labs, Inc. | Apparatus and method for synthesizing pseudo-stereophonic outputs from a monophonic input |
US20050129248A1 (en) * | 2003-12-12 | 2005-06-16 | Alan Kraemer | Systems and methods of spatial image enhancement of a sound source |
US6937737B2 (en) | 2003-10-27 | 2005-08-30 | Britannia Investment Corporation | Multi-channel audio surround sound from front located loudspeakers |
US7031474B1 (en) | 1999-10-04 | 2006-04-18 | Srs Labs, Inc. | Acoustic correction apparatus |
US20060269069A1 (en) * | 2005-05-31 | 2006-11-30 | Polk Matthew S Jr | Compact audio reproduction system with large perceived acoustic size and image |
US20090175472A1 (en) * | 2006-04-19 | 2009-07-09 | Embracing Sound Experience Ab | Loudspeaker Device |
US20100298136A1 (en) * | 2006-03-29 | 2010-11-25 | Bayer Cropscience Ag | Active ingredient combinations with insecticidal properties |
US7987281B2 (en) | 1999-12-10 | 2011-07-26 | Srs Labs, Inc. | System and method for enhanced streaming audio |
US8050434B1 (en) | 2006-12-21 | 2011-11-01 | Srs Labs, Inc. | Multi-channel audio enhancement system |
US9071897B1 (en) | 2013-10-17 | 2015-06-30 | Robert G. Johnston | Magnetic coupling for stereo loudspeaker systems |
US9084047B2 (en) | 2013-03-15 | 2015-07-14 | Richard O'Polka | Portable sound system |
US9088858B2 (en) | 2011-01-04 | 2015-07-21 | Dts Llc | Immersive audio rendering system |
USD740784S1 (en) | 2014-03-14 | 2015-10-13 | Richard O'Polka | Portable sound device |
US9258664B2 (en) | 2013-05-23 | 2016-02-09 | Comhear, Inc. | Headphone audio enhancement system |
US10149058B2 (en) | 2013-03-15 | 2018-12-04 | Richard O'Polka | Portable sound system |
US10327064B2 (en) | 2016-10-27 | 2019-06-18 | Polk Audio, Llc | Method and system for implementing stereo dimensional array signal processing in a compact single enclosure active loudspeaker product |
US10327086B2 (en) * | 2017-04-27 | 2019-06-18 | Polk Audio, Llc | Head related transfer function equalization and transducer aiming of stereo dimensional array (SDA) loudspeakers |
WO2020102183A1 (en) | 2018-11-15 | 2020-05-22 | Polk Audio, Llc | Loudspeaker system with overhead sound image generating elevation module |
US11937066B2 (en) | 2019-03-07 | 2024-03-19 | Polk Audio, Llc | Active cancellation of a height-channel soundbar array's forward sound radiation |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4569074A (en) * | 1984-06-01 | 1986-02-04 | Polk Audio, Inc. | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
AT394650B (en) * | 1988-10-24 | 1992-05-25 | Akg Akustische Kino Geraete | ELECTROACOUSTIC ARRANGEMENT FOR PLAYING STEREOPHONER BINAURAL AUDIO SIGNALS VIA HEADPHONES |
JP2001340522A (en) * | 2000-05-31 | 2001-12-11 | Heiwa Corp | Game machine frame body |
US8306243B2 (en) * | 2007-08-13 | 2012-11-06 | Mitsubishi Electric Corporation | Audio device |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3697692A (en) * | 1971-06-10 | 1972-10-10 | Dynaco Inc | Two-channel,four-component stereophonic system |
GB1425519A (en) * | 1972-10-13 | 1976-02-18 | Sony Corp | Stereophonic signal reproducing apparatus |
GB1459188A (en) * | 1973-01-13 | 1976-12-22 | Emi Ltd | Apparatus for producing pseudo quadraphonic signals from stereo signals |
US4058675A (en) * | 1975-06-19 | 1977-11-15 | Sansui Electric Co., Ltd. | Loudspeaker system for use in a stereophonic sound reproduction system |
US4199658A (en) * | 1977-09-10 | 1980-04-22 | Victor Company Of Japan, Limited | Binaural sound reproduction system |
US4219696A (en) * | 1977-02-18 | 1980-08-26 | Matsushita Electric Industrial Co., Ltd. | Sound image localization control system |
GB2074823A (en) * | 1980-03-12 | 1981-11-04 | Cohen J M | Stereophonic audio reproduction system |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS476801U (en) * | 1971-02-15 | 1972-09-25 |
-
1982
- 1982-05-28 US US06/383,151 patent/US4489432A/en not_active Expired - Lifetime
-
1983
- 1983-05-25 GB GB08314479A patent/GB2122459B/en not_active Expired
- 1983-05-27 JP JP58092567A patent/JP2529933B2/en not_active Expired - Lifetime
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3697692A (en) * | 1971-06-10 | 1972-10-10 | Dynaco Inc | Two-channel,four-component stereophonic system |
GB1367705A (en) * | 1971-06-10 | 1974-09-18 | Dynaco Inc | Audio reproduction systems |
GB1425519A (en) * | 1972-10-13 | 1976-02-18 | Sony Corp | Stereophonic signal reproducing apparatus |
GB1459188A (en) * | 1973-01-13 | 1976-12-22 | Emi Ltd | Apparatus for producing pseudo quadraphonic signals from stereo signals |
US4058675A (en) * | 1975-06-19 | 1977-11-15 | Sansui Electric Co., Ltd. | Loudspeaker system for use in a stereophonic sound reproduction system |
US4219696A (en) * | 1977-02-18 | 1980-08-26 | Matsushita Electric Industrial Co., Ltd. | Sound image localization control system |
US4199658A (en) * | 1977-09-10 | 1980-04-22 | Victor Company Of Japan, Limited | Binaural sound reproduction system |
GB2074823A (en) * | 1980-03-12 | 1981-11-04 | Cohen J M | Stereophonic audio reproduction system |
US4308423A (en) * | 1980-03-12 | 1981-12-29 | Cohen Joel M | Stereo image separation and perimeter enhancement |
Cited By (73)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4612663A (en) * | 1984-03-26 | 1986-09-16 | Holbrook Kyle A | Multichannel audio reproduction system |
US4630298A (en) * | 1985-05-30 | 1986-12-16 | Polk Matthew S | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
US4638505A (en) * | 1985-08-26 | 1987-01-20 | Polk Audio Inc. | Optimized low frequency response of loudspeaker systems having main and sub-speakers |
US4748669A (en) * | 1986-03-27 | 1988-05-31 | Hughes Aircraft Company | Stereo enhancement system |
US5034983A (en) * | 1987-10-15 | 1991-07-23 | Cooper Duane H | Head diffraction compensated stereo system |
US5136651A (en) * | 1987-10-15 | 1992-08-04 | Cooper Duane H | Head diffraction compensated stereo system |
US4910779A (en) * | 1987-10-15 | 1990-03-20 | Cooper Duane H | Head diffraction compensated stereo system with optimal equalization |
US4975954A (en) * | 1987-10-15 | 1990-12-04 | Cooper Duane H | Head diffraction compensated stereo system with optimal equalization |
US4841572A (en) * | 1988-03-14 | 1989-06-20 | Hughes Aircraft Company | Stereo synthesizer |
US4888804A (en) * | 1988-05-12 | 1989-12-19 | Gefvert Herbert I | Sound reproduction system |
US5117459A (en) * | 1990-05-03 | 1992-05-26 | Chicago Steel Rule Die & Fabricators Co. | Ambient imaging loudspeaker system |
US5274708A (en) * | 1992-06-01 | 1993-12-28 | Fusan Labs, Inc. | Digital stereo sound enhancement unit and method |
US5594801A (en) * | 1994-05-26 | 1997-01-14 | Mcshane; Charles L. | Ambient expansion loudspeaker system |
US5661808A (en) * | 1995-04-27 | 1997-08-26 | Srs Labs, Inc. | Stereo enhancement system |
US7636443B2 (en) | 1995-04-27 | 2009-12-22 | Srs Labs, Inc. | Audio enhancement system |
US5892830A (en) * | 1995-04-27 | 1999-04-06 | Srs Labs, Inc. | Stereo enhancement system |
US6597791B1 (en) | 1995-04-27 | 2003-07-22 | Srs Labs, Inc. | Audio enhancement system |
US20040005063A1 (en) * | 1995-04-27 | 2004-01-08 | Klayman Arnold I. | Audio enhancement system |
US20060062395A1 (en) * | 1995-07-28 | 2006-03-23 | Klayman Arnold I | Acoustic correction apparatus |
US6718039B1 (en) | 1995-07-28 | 2004-04-06 | Srs Labs, Inc. | Acoustic correction apparatus |
US7555130B2 (en) | 1995-07-28 | 2009-06-30 | Srs Labs, Inc. | Acoustic correction apparatus |
US5850453A (en) * | 1995-07-28 | 1998-12-15 | Srs Labs, Inc. | Acoustic correction apparatus |
US7043031B2 (en) | 1995-07-28 | 2006-05-09 | Srs Labs, Inc. | Acoustic correction apparatus |
US20040247132A1 (en) * | 1995-07-28 | 2004-12-09 | Klayman Arnold I. | Acoustic correction apparatus |
US5970152A (en) * | 1996-04-30 | 1999-10-19 | Srs Labs, Inc. | Audio enhancement system for use in a surround sound environment |
US7200236B1 (en) | 1996-11-07 | 2007-04-03 | Srslabs, Inc. | Multi-channel audio enhancement system for use in recording playback and methods for providing same |
US20090190766A1 (en) * | 1996-11-07 | 2009-07-30 | Srs Labs, Inc. | Multi-channel audio enhancement system for use in recording playback and methods for providing same |
US7492907B2 (en) | 1996-11-07 | 2009-02-17 | Srs Labs, Inc. | Multi-channel audio enhancement system for use in recording and playback and methods for providing same |
US8472631B2 (en) | 1996-11-07 | 2013-06-25 | Dts Llc | Multi-channel audio enhancement system for use in recording playback and methods for providing same |
US5912976A (en) * | 1996-11-07 | 1999-06-15 | Srs Labs, Inc. | Multi-channel audio enhancement system for use in recording and playback and methods for providing same |
US6281749B1 (en) | 1997-06-17 | 2001-08-28 | Srs Labs, Inc. | Sound enhancement system |
US20040005066A1 (en) * | 1998-10-13 | 2004-01-08 | Kraemer Alan D. | Apparatus and method for synthesizing pseudo-stereophonic outputs from a monophonic input |
US6590983B1 (en) | 1998-10-13 | 2003-07-08 | Srs Labs, Inc. | Apparatus and method for synthesizing pseudo-stereophonic outputs from a monophonic input |
US7031474B1 (en) | 1999-10-04 | 2006-04-18 | Srs Labs, Inc. | Acoustic correction apparatus |
US7907736B2 (en) | 1999-10-04 | 2011-03-15 | Srs Labs, Inc. | Acoustic correction apparatus |
US7987281B2 (en) | 1999-12-10 | 2011-07-26 | Srs Labs, Inc. | System and method for enhanced streaming audio |
US8751028B2 (en) | 1999-12-10 | 2014-06-10 | Dts Llc | System and method for enhanced streaming audio |
US20020161882A1 (en) * | 2001-04-30 | 2002-10-31 | Masayuki Chatani | Altering network transmitted content data based upon user specified characteristics |
US8108509B2 (en) | 2001-04-30 | 2012-01-31 | Sony Computer Entertainment America Llc | Altering network transmitted content data based upon user specified characteristics |
US20070168359A1 (en) * | 2001-04-30 | 2007-07-19 | Sony Computer Entertainment America Inc. | Method and system for proximity based voice chat |
US20020181718A1 (en) * | 2001-05-29 | 2002-12-05 | Pioneer Corporation | Audio apparatus |
JP2007510334A (en) * | 2003-10-27 | 2007-04-19 | ブリタニア インベストメント コーポレーション | Multi-channel audio surround sound system from front loudspeakers |
US20050226425A1 (en) * | 2003-10-27 | 2005-10-13 | Polk Matthew S Jr | Multi-channel audio surround sound from front located loudspeakers |
US6937737B2 (en) | 2003-10-27 | 2005-08-30 | Britannia Investment Corporation | Multi-channel audio surround sound from front located loudspeakers |
JP4743790B2 (en) * | 2003-10-27 | 2011-08-10 | ブリタニア インベストメント コーポレーション | Multi-channel audio surround sound system from front loudspeakers |
US7231053B2 (en) | 2003-10-27 | 2007-06-12 | Britannia Investment Corp. | Enhanced multi-channel audio surround sound from front located loudspeakers |
US20050129248A1 (en) * | 2003-12-12 | 2005-06-16 | Alan Kraemer | Systems and methods of spatial image enhancement of a sound source |
US7522733B2 (en) | 2003-12-12 | 2009-04-21 | Srs Labs, Inc. | Systems and methods of spatial image enhancement of a sound source |
US20060269069A1 (en) * | 2005-05-31 | 2006-11-30 | Polk Matthew S Jr | Compact audio reproduction system with large perceived acoustic size and image |
US7817812B2 (en) | 2005-05-31 | 2010-10-19 | Polk Audio, Inc. | Compact audio reproduction system with large perceived acoustic size and image |
US20100298136A1 (en) * | 2006-03-29 | 2010-11-25 | Bayer Cropscience Ag | Active ingredient combinations with insecticidal properties |
US8620010B2 (en) * | 2006-04-19 | 2013-12-31 | Embracing Sound Experience Ab | Loudspeaker device |
US20090175472A1 (en) * | 2006-04-19 | 2009-07-09 | Embracing Sound Experience Ab | Loudspeaker Device |
US8509464B1 (en) | 2006-12-21 | 2013-08-13 | Dts Llc | Multi-channel audio enhancement system |
US9232312B2 (en) | 2006-12-21 | 2016-01-05 | Dts Llc | Multi-channel audio enhancement system |
US8050434B1 (en) | 2006-12-21 | 2011-11-01 | Srs Labs, Inc. | Multi-channel audio enhancement system |
US10034113B2 (en) | 2011-01-04 | 2018-07-24 | Dts Llc | Immersive audio rendering system |
US9088858B2 (en) | 2011-01-04 | 2015-07-21 | Dts Llc | Immersive audio rendering system |
US9154897B2 (en) | 2011-01-04 | 2015-10-06 | Dts Llc | Immersive audio rendering system |
US9084047B2 (en) | 2013-03-15 | 2015-07-14 | Richard O'Polka | Portable sound system |
US10149058B2 (en) | 2013-03-15 | 2018-12-04 | Richard O'Polka | Portable sound system |
US10771897B2 (en) | 2013-03-15 | 2020-09-08 | Richard O'Polka | Portable sound system |
US9560442B2 (en) | 2013-03-15 | 2017-01-31 | Richard O'Polka | Portable sound system |
US10284955B2 (en) | 2013-05-23 | 2019-05-07 | Comhear, Inc. | Headphone audio enhancement system |
US9866963B2 (en) | 2013-05-23 | 2018-01-09 | Comhear, Inc. | Headphone audio enhancement system |
US9258664B2 (en) | 2013-05-23 | 2016-02-09 | Comhear, Inc. | Headphone audio enhancement system |
US9071897B1 (en) | 2013-10-17 | 2015-06-30 | Robert G. Johnston | Magnetic coupling for stereo loudspeaker systems |
USD740784S1 (en) | 2014-03-14 | 2015-10-13 | Richard O'Polka | Portable sound device |
US10327064B2 (en) | 2016-10-27 | 2019-06-18 | Polk Audio, Llc | Method and system for implementing stereo dimensional array signal processing in a compact single enclosure active loudspeaker product |
US10327086B2 (en) * | 2017-04-27 | 2019-06-18 | Polk Audio, Llc | Head related transfer function equalization and transducer aiming of stereo dimensional array (SDA) loudspeakers |
WO2020102183A1 (en) | 2018-11-15 | 2020-05-22 | Polk Audio, Llc | Loudspeaker system with overhead sound image generating elevation module |
US12120494B2 (en) | 2018-11-15 | 2024-10-15 | Polk Audio, Llc | Loudspeaker system with overhead sound image generating (e.g., ATMOS™) elevation module and method and apparatus for direct signal cancellation |
US11937066B2 (en) | 2019-03-07 | 2024-03-19 | Polk Audio, Llc | Active cancellation of a height-channel soundbar array's forward sound radiation |
Also Published As
Publication number | Publication date |
---|---|
JPS5932300A (en) | 1984-02-21 |
GB2122459B (en) | 1986-04-23 |
GB8314479D0 (en) | 1983-06-29 |
JP2529933B2 (en) | 1996-09-04 |
GB2122459A (en) | 1984-01-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4489432A (en) | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image | |
US4569074A (en) | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image | |
US4497064A (en) | Method and apparatus for reproducing sound having an expanded acoustic image | |
US4630298A (en) | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image | |
US4819269A (en) | Extended imaging split mode loudspeaker system | |
US4199658A (en) | Binaural sound reproduction system | |
US4058675A (en) | Loudspeaker system for use in a stereophonic sound reproduction system | |
US6236730B1 (en) | Full sound enhancement using multi-input sound signals | |
US5117459A (en) | Ambient imaging loudspeaker system | |
US4567607A (en) | Stereo image recovery | |
US4069394A (en) | Stereophonic sound reproduction system | |
US5181247A (en) | Sound image enhancing | |
US4359605A (en) | Monaural signal to artificial stereo signals convertings and processing circuit for headphones | |
JPH09505702A (en) | Binaural signal processor | |
US4847904A (en) | Ambient imaging loudspeaker system | |
US6222930B1 (en) | Method of reproducing sound | |
US4087631A (en) | Projected sound localization headphone apparatus | |
CA1198683A (en) | Method and apparatus for reproducing sound having a realistic ambient field and acoustic image | |
JPH07503112A (en) | speaker system | |
US7796766B2 (en) | Audio center channel phantomizer | |
JPH0662486A (en) | Acoustic reproducing device | |
US3162727A (en) | Stereophonic reverberation system | |
JPS61237600A (en) | Acoustic device | |
JPS6322800Y2 (en) | ||
JPH05191898A (en) | Sound image expansion device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: POLK AUDIO, INC. 1915 ANNAPOLIS ROAD, BALTIMORE, M Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:POLK, MATTHEW S.;REEL/FRAME:004011/0078 Effective date: 19820527 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: POLK INVESTMENT CORPORATION, SUITE 1704, BANK OF D Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:POLK AUDIO, INC., A MD. CORP.;REEL/FRAME:004772/0384 Effective date: 19870928 Owner name: POLK INVESTMENT CORPORATION,DELAWARE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:POLK AUDIO, INC., A MD. CORP.;REEL/FRAME:004772/0384 Effective date: 19870928 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: PAT HLDR NO LONGER CLAIMS SMALL ENT STAT AS SMALL BUSINESS (ORIGINAL EVENT CODE: LSM2); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: PAT HOLDER CLAIMS SMALL ENTITY STATUS - SMALL BUSINESS (ORIGINAL EVENT CODE: SM02); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 12 |